Column Internals & Tower Packing

Column Packing [Colpack]

Colpack has, over the years, become generally accepted as the most efficient packing for distillation towers operating at reduced pressure. It is ideal for the separation of heat-sensitive and close-boiling fractions, where many theoretical stages and low pressure drop are required. Colpack offers a precise solution to this challenge.

Construction

Colpacks are fabricated by knitting bunched fine wires of filaments (0.01 mm), which are then crimped and wound into rolls of the desired column diameter.
Any material that can be drawn into fine wire or filament may be used, but SS 304 and SS 316 are commonly stocked. Higher alloys are available upon request.

Installation

• Supplied as 150 mm high packings, matching the nominal bore of the column.

• Requires only simple support—typically two bars at right angles or parallel bars (6-inch spacing) for large towers.

• Packed from the top, ensuring the tower is free of internal projections.

• Push gently down to the support grid using a wooden disc mounted on a pole to prevent damage.

• Alternate crimp directions should be maintained for optimal performance.

Salient Features

1. Easily retrofitted to existing columns by replacing random packing, leading to:

   • Improved product quality

   • Higher production capacity

   • Lower pressure drop

2. Low bulk density (432 kg/m³) results in:

   • Lighter columns

   • Reduced structural foundation needs

   • Lower insulation, piping, and installation costs

   • Possible column diameter reduction

3. High voidage allows free flow of liquid and vapor, leading to:

   • Extremely low pressure drop per unit height

4. High surface area (1780 m²/m³) enables:

   • Intimate vapor-liquid contact

   • Lower HETP values

5. HETP < 15 cm over the entire velocity range

6. Flooding velocity is 2 to 2.5 times higher than conventional packings, allowing:

   • Smaller column diameters or

   • Increased throughput

Applications

1. Vacuum distillation, where pressure drop is critical and high separation efficiency is needed.

2. Thermal-sensitive component separation.

3. Very low superficial velocities (as low as 0.1 cm/sec).

4. Pollution control, especially in the biological oxidation of liquid effluents.

5. Manufacture of organic compounds.

6. Outperforms conventional packings in both performance and reliability.

Shreewire’s Knitted Mesh Products
Shreewire produces a high-quality, versatile knitted mesh using a wide range of materials, offering a high degree of creativity and expertise. Our skilled design and development team ensures that the correct characteristics and specifications are chosen for each individual application. Customizable features include wire diameter (0.08 to 0.5mm), as well as the number, shape, and size of the stitch.

The majority of materials we use are 100% recyclable, addressing growing global concerns across various industries. With access to a vast selection of raw materials, we offer expert guidance to ensure optimum performance and long life expectancy in nearly any application.

Materials Readily Available:

• Stainless Steel Grades: AISI 302, 304, 316L, 321, 309, 314, 310S

Materials Available on Demand:

• Super Alloys: Inconel 601, Incoloy DS, Hastelloy, Carpenter 20, Monel

• Others: Aluminium, Copper, Brass, Mild Steel (Plain and Galvanized), Polypropylene

• And other continuous filament materials supplied as wire or yarn

Applications:

• Knitted Mesh Rolls

• Demister Mist Eliminators

• Clear-mesh

• Anti-vandal Mesh

• Grease Filters and Framed Filters

• Anti-Vibration Mounts

• Heavy-Duty Seals

• RFI / EMI Shielding

• Vibration and Shock Absorption

• Air and Liquid Filtration

• Noise Suppression

• Heat Transfer and Insulation

• Mist Elimination and Process Separation

• Flame Arrestors

• Engine Catalysts

Knitted Wire Mesh Forms:

• Filters

• Oil and Air Breather Elements

• Catalytic Converter Mesh

• Insulator Blanket Mesh

• Mufflers and Silencers

• Copper Mesh Oil-Bath Separators

• Mist Elimination Pads

• Ground Wire Mesh

Model Type – 1: Blade Design Mixer

• Mixer Type: SS – 316 Material

• Viscosity Range: Less than 1500 cps

• Reynolds Number: Greater than 500

• Size Range: ½" to 14"

• Application: Mixing products into water or water-like fluids

SW-SMx-01: Used for low viscosity. The faster the fluid moves, the faster the mixing. Ideal for mixing products into water or water-like fluids.

Model Type – 2: Helical Design Mixer

• Model: SW-SMx-02

• Application: Used for high viscosity blending and when the fluid moves more slowly through the mixer

• Material: SS – 316

• Viscosity Range: Greater than 1500 cps

• Reynolds Number: Less than 500

• Size Range: ½" to 14"

• Application Areas: Epoxy blending, fruits into yogurt, cookies into ice cream, thermal homogeneity, slurry suspension, folding/stripping

Customer Benefits

• Excellent mixing and dispersing, even with widely differing fluid viscosities

• Compact designs

• Reduced product degradation due to very short residence time

• Mixing of sensitive products under minimal shear stress

• No deposits and blockages due to excellent cross-mixing

Advantages

• High level of mixing efficiency – formation of byproducts is dramatically reduced

• Low energy consumption

• Easy installation

• Available in all standard pipe sizes, and for open channel designs, available in any size with no upper limit

Industries Served

• Pulp and Paper Processing

• Pharmaceuticals

• Oil Refining

• Petrochemicals

• Food Processing

• Natural Gas Processing

• Water and Waste Water Treatment

Design Calculations

Reynolds Number Formula:
Re = Dvρ/µ

Number of Elements Required:

• Re < 10 → 24–36 elements

• 10 < Re < 100 → 18 elements

• 100 < Re < 1000 → 12 elements

• 1000 < Re < 10000 → 6 elements

• Re > 10000 → 4 elements

Pressure Drop Calculation

ΔP = 3.061 × 10⁶ × f × n × smxpx(u)² × E

G Value Calculation

G = v(hf × g × ρ / μt)

Pipe Diameter (D in meters)

 

D = √(4Q / πv)

Shreewire Stripping Column – High-Efficiency VOC & Solvent Removal System for Industrial Applications Product Overview

Shreewire Stripping Columns are engineered systems designed for the efficient removal of volatile organic compounds (VOCs), such as benzene, toluene, xylene, and low-boiling solvents like methanol and ethanol from water streams. These columns are vital in industries requiring liquid purification or solvent recovery, including chemical, petrochemical, oil & gas, and wastewater treatment sectors.

Each column is configured based on process requirements and fluid composition, and is available in two main designs: Tray Columns and Packed Columns.

Tray Column Design

Tray columns (also known as plate columns) are among the most widely used mass transfer devices in industrial separation. The number of trays and stages is precisely determined based on required separation efficiency and product purity.

Types of Trays Offered:

• Sieve Tray

• Bubble Cap Tray

• Moving Valve Tray

• Fixed Valve Tray

Key Benefits:

• Modular construction for easier maintenance

• Can be partially replaced with packing to debottleneck capacity

• Designed for excellent vapor-liquid contact

Material of Construction (MOC):

• All Stainless Steel (SS304 / SS316)

Packed Column Design

Packed columns provide high surface area for enhanced vapor-liquid interaction, resulting in greater separation efficiency per unit height compared to tray columns. Ideal for processes requiring compact column design and low-pressure drop.

Internal Components:

1. Mist Eliminator (Demister Pad)

   • Knitted wire mesh pad ensures 99%+ droplet separation down to 5 microns

   • Low-pressure drop (approx. 25 mm WC)

   • Maintenance-free and easy to install

2. Liquid Distributor

   • Ensures uniform liquid distribution across the packed bed

   • Prevents maldistribution, flooding, and inefficient mass transfer

3. Bed Limiter

   • Prevents displacement or fluidization of packing under high vapor load

   • Mounted on top of the packing layer

4. Packing Options

   • Random Packing: Metal/Plastic types (e.g., Raschig rings, Pall rings)

     • Maximizes surface-to-volume ratio, minimizes pressure drop

   • Structured Packing: Corrugated, honeycomb-type shapes

     • Precisely engineered to allow maximum surface area with low resistance

     • Suitable for high-efficiency, low-pressure operations

5. Packing Support Plate

   • Supports the weight of the packed bed

   • Designed with large open area to maintain uniform liquid and vapor flow

   • Prevents flooding and ensures mechanical integrity

Material of Construction (MOC):

• All Stainless Steel (SS304 / SS316)

• PP (Polypropylene) – for specific chemical resistance needs

Applications

• Removal of volatile hydrocarbons and chlorinated solvents

• Water purification and effluent treatment

• Solvent recovery systems

• Chemical process stripping and regeneration units

Key Features

• Tailored design with tray or packed configuration

• High VOC removal efficiency

• Engineered internals for optimal gas-liquid contact

• Low maintenance and robust construction

• Available in wide material choices for corrosive or high-temperature services